Filters Modern diesel engines emit a substantially smaller quantity of soot particles in comparison to older diesel engines. In this connection, diesel particulate filters lower the particulate emission significantly by providing means to retain even the finest particles that are produced in the combustion process of diesel fuel.
Known are diesel particulate filters (DPFs) made from extruded ceramic material; also DPFs on the basis of wound elements are known. For example, WO 2006/005668 discloses a method for producing a ceramic filter element of an exhaust gas filter for internal combustion engines. In this connection, first a combustible non-ceramic support web is impregnated with a ceramic slip or slurry and, subsequently, after having been formed to the desired geometric shape, is fired to such an extent that the support web is combusted and a rigid filter body remains. Such porous ceramic components can be used, for example, as catalyst supports or for filtration applications, primarily in high temperature applications.
These diesel particulate filters of the prior art have inter alia the disadvantage that when being mounted in a housing, the so-called canning process, they cause problems because, as a result of their smooth surface, there is no proper grip or engagement of the ceramic mat used for installation between the DPF and the sheet metal housing. Therefore, the filters of the prior art require a stronger compression of the ceramic mat.
There is therefore the need to provide a ceramic filter element, in particular a diesel particulate filter, that avoids these disadvantages of the prior art.